Prosthesis with guide lumen

ABSTRACT

Tubular prosthesis for deployment in a human body passageway comprises a tubular member adapted for placement in a passageway in a human body and a tube. The tubular member has a tubular wall, first and second end openings, and a side opening formed in the tubular wall between the first and second end openings. The tube has a first end portion and a second end portion. The first end portion of the tube is disposed in the tubular member and has an opening arranged relative to the side opening such that an elongated element (e.g., a guidewire) can be passed through the tube and out from the side opening in the tubular wall where it can enter a branch passageway. The tube can be releasably secured to the tubular member in such as manner that it can be detached from the tubular member and withdrawn after the elongated element is passed through the side opening and placed in a desired position.

FIELD OF THE INVENTION

The invention relates to apparatus and methods for endoluminal deliveryof devices such as guidewires, for example, to branch passageways in ahuman body.

BACKGROUND OF THE INVENTION

Tubular prostheses such as stents, grafts, and stent-grafts (e.g.,stents having an inner and/or outer covering comprising graft materialand which may be referred to as covered stents) have been widely used intreating abnormalities in passageways in the human body. In vascularapplications, these devices often are used to replace or bypassoccluded, diseased or damaged blood vessels such as stenotic oraneurysmal vessels. For example, it is well known to use stent-grafts,which comprise biocompatible graft material (e.g., Dacron® or expanded,porous polytetrafluoroethylene (ePTFE)) supported by a framework (e.g.,one or more stent or stent-like structures), to treat or isolateaneurysms. The framework provides mechanical support and the graftmaterial or liner provides a blood barrier.

Aneurysms generally involve abnormal widening of a duct or canal such asa blood vessel and generally appear in the form of a sac formed by theabnormal dilation of the duct or vessel wall. The abnormally dilatedwall typically is weakened and susceptible to rupture. Aneurysms canoccur in blood vessels such as in the abdominal aorta. An abdominalaortic aneurysm generally extends below the renal arteries and extendsdistally to or toward the iliac arteries.

In treating an aneurysm with a stent-graft, the stent-graft typically isplaced so that one end of the stent-graft is situated proximally orupstream of the diseased portion of the vessel and the other end of thestent-graft is situated distally or downstream of the diseased portionof the vessel. In this manner, the stent-graft extends through theaneurysmal sac and beyond the proximal and distal ends thereof toreplace or bypass the dilated wall. The graft material typically forms ablood containing lumen to facilitate endovascular exclusion of theaneurysm.

Such prostheses can be implanted in an open surgical procedure or with aminimally invasive approach. Minimally invasive endovascular stent-graftdelivery generally is preferred over traditional open surgery techniqueswhere the area of diseased vessel is surgically opened, the vesselbypassed and cut, and a prosthesis (e.g., stent-graft) sutured intoposition. The endovascular approach generally involves cutting throughthe skin to access a lumen or vasculature. Alternatively, lumenar orvascular access may be achieved percutaneously via successive dilationat a less traumatic entry point. Once access is achieved, thestent-graft can be routed through the vasculature to the target site.For example, a stent-graft delivery catheter loaded with a stent-graftcan be percutaneously introduced into the vasculature (e.g., into afemoral artery) and the stent-graft delivered endovascularly to theaneurysm where it is deployed. When using an expandable stent-graft,balloon catheters generally are used to expand the stent-graft after itis positioned at the target site. When, however, a self-expandingstent-graft is used, the stent-graft generally is radially compressed orfolded and placed at the distal end of a sheath or delivery catheter andallowed to expand upon deployment from the sheath or catheter at thetarget site. More specifically, a delivery catheter having coaxial innerand outer tubes arranged for relative axial movement therebetween can beused and loaded with a compressed self-expanding stent-graft. Thestent-graft is positioned within the distal end of the outer tube(sheath) and in front of the inner tube (plunger). Once the catheter ispositioned for deployment of the stent-graft at the target site, theplunger is held stationary and the outer tube withdrawn so that thestent-graft is gradually exposed and allowed to expand. An exemplarystent-graft delivery system is described in U.S. Patent ApplicationPublication No. 2004/0093063, which published on May 13, 2004 to Wrightet al. and is entitled Controlled Deployment Delivery System.

Although the endovascular approach is much less invasive, and usuallyrequires less recovery time and involves less risk of complication ascompared to open surgery, there can be concerns with management ofendoluminal devices such as guidewires, especially in relatively complexapplications. For example, branch vessel techniques have involved thedelivery of a main device (e.g., a graft or stent-graft) and then asecondary device (e.g., a graft or stent-graft) through a fenestrationor side opening in the main device and into a branch vessel.

The procedure becomes more complicated when more than one branch vesselis treated. One example is when an aortic abdominal aneurysm is to betreated and its proximal neck is diseased or damaged to the extent thatit cannot support a connection and/or seal with a prosthesis. In thiscase, grafts or stent-grafts have been provided with fenestrations oropenings formed in their side wall below a proximal portion thereof. Theproximal portion is secured to the aortic wall above the renal arteriesand the fenestrations or openings are aligned with the renal arteries.

To ensure alignment of the prostheses fenestrations and branch vessels,current techniques involve placing guidewires through each fenestrationand branch vessel (e.g., artery) prior to releasing the main device orprosthesis. This involves manipulation of multiple wires in the aorta atthe same time, while the delivery system and stent-graft are still inthe aorta. In addition, an angiographic catheter, which may have beenused to provide branch vessel detection and preliminary prosthesispositioning, may still be in the aorta. The foregoing approach can causeseveral concerns. The procedure may give rise to branch lumen guidewireentanglement with other wires and/or elements of the delivery system.There may be difficulty in accessing the fenestrations with theguidewires. Further, wires may fall out of the branch lumens andfenestrations, while the surgeon manipulates other portions of thedelivery system or main device.

There remains a need to develop and/or improve delivery apparatus andapproaches for endoluminal or endovascular prostheses and/or guidedevice placement.

SUMMARY OF THE INVENTION

The present invention involves improvements in prosthesis and/or guidedevice placement and overcomes disadvantages of prior art.

According to one embodiment of the invention, a tubular prosthesis fordeployment in a human body passageway comprises a tubular member adaptedfor placement in a passageway in a human body and a tube. The tubularmember has a tubular wall, first and second end opening, and a sideopening formed in the tubular wall between the first and second endopenings. The tube has a first end portion and a second end portion, thefirst end portion being disposed in the tubular member and extendingtoward the side opening. The tube can be releasably secured to thetubular member so that an elongated element (e.g., a guidewire) can bepassed through the tube and out from the side opening in the tubularwall and the tube detached from the tubular member so that it can bemoved relative to and withdrawn over the elongated element after theelongated element is placed in a desired position.

According to another embodiment of the invention, a tubular prosthesisdelivery system comprises a delivery catheter having a proximal endportion and a distal end portion, a tubular prosthesis comprising atubular wall, first and second end openings, and a side opening formedin the tubular wall between the first and second end openings. Theprosthesis is positioned in the distal end portion of the deliverycatheter. A tube having a first end portion and a second end portion isprovided with the tube first end portion being disposed in the tubularprosthesis and having an end opening in the vicinity of the side openingand the tube second end portion extending to the proximal end portion ofthe delivery catheter.

According to another embodiment of the invention, a method of deliveringa guide to a branch lumen comprises delivering a tubular prosthesis,which includes a side opening, an inner wall surface and a tubeextending along a portion of the inner wall surface and toward the sideopening, through a first passageway in a human body to a site where asecond passageway branches from the first passageway; advancing a guideelement through the tube and side opening and into the secondpassageway; and removing the tube from the tubular prosthesis.

Other features, advantages, and embodiments according to the inventionwill be apparent to those skilled in the art from the followingdescription and accompanying drawings, wherein, for purposes ofillustration only, specific embodiments according to the invention areset forth in detail.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a prosthesis having guide device lumensin accordance with one embodiment of the present invention.

FIG. 2A is another diagrammatic view of the prosthesis of FIG. 1 showingguide devices, which can be guidewires, positioned in the prosthesisguide device tubes or lumens prior to deployment therefrom.

FIG. 2B depicts the prosthesis of FIG. 2A with the guide devicesdeployed.

FIG. 3A is a diagrammatic view of another embodiment of the inventionwith guide devices positioned in prosthesis guide device lumens prior todeployment therefrom.

FIG. 3B depicts the embodiment of FIG. 3A with the guide devicesdeployed.

FIG. 4A illustrates a variation of a prosthesis guide tube that forms aguide device lumen in accordance with the invention.

FIG. 4B diagrammatically illustrates another prosthesis in accordancewith the invention with a pair of guide tubes of FIG. 4A and guidedevices positioned therein prior to deployment therefrom.

FIG. 4C depicts the prosthesis of FIG. 4B with the guide devicesdeployed.

FIG. 5 diagrammatically illustrates a prosthesis delivery system withguide device lumens in accordance with the invention.

FIGS. 6A-C illustrate a method using the system of FIG. 5 in accordancewith the invention; where FIG. 6A illustrates endoluminally positioningthe prosthesis at a target site, FIG. 6B illustrates advancing the guidedevices into branch lumens or vessels, and FIG. 6C illustrateswithdrawal of the prosthesis guide tubes and delivery apparatus afterthe guide devices have been positioned in the branch lumens and theprosthesis fully deployed.

FIG. 7 illustrates a bifurcated embodiment of a prosthesis in accordancewith the invention showing withdrawal of the prosthesis guide tubes anddelivery apparatus after the guide devices have been positioned in thebranch lumens and the prosthesis fully deployed.

FIG. 8 is a front elevational view of a stent-graft in accordance withthe invention.

FIG. 9 is a front elevational view of a bifurcated stent-graft inaccordance with the invention.

FIG. 10A illustrates a known prosthesis restraint for releasablyrestraining the proximal end of a prosthesis.

FIGS. 10B-D diagrammatically illustrate a prosthesis delivery system inaccordance with the invention; where FIG. 10B illustrates the prosthesisdelivery system including the restraint of FIG. 10A, FIG. 10Cillustrates the prosthesis of FIG. 10B partially deployed, and FIG. 10Dillustrates the prosthesis of FIG. 10C with its proximal end deployed.

DETAILED DESCRIPTION

The following description will be made with reference to the drawingswhere when referring to the various figures, it should be understoodthat like numerals or characters indicate like elements.

Embodiments according to the invention involve prostheses thatfacilitate directing and/or delivering devices from one passageway in ahuman body to another. In one example case, a prosthesis, which has anopening (e.g., an opening in a side wall thereof), has disposed thereina tube. The tube, which can be dedicated to guidance and/or delivery ofone or more selected devices including, but not limited to guidewires,guide catheters, and/or steerable guide catheters, has an outlet that isin the vicinity of the opening. The outlet therefore can be alignedwith, adjacent to or overlapping the opening. The prosthesis can bepositioned in a lumen with its side wall opening in the vicinity of(e.g., aligned with, adjacent to, or overlapping) a branch lumen and adevice introduced into the branch lumen from the prosthesis tube andside wall opening. For example, the prosthesis can be used to deliver aguidewire into a branch passageway for subsequent delivery of asecondary prosthesis over the guidewire so as to pass through the firstpassageway and into the second passageway. In such a case, the guidewiredelivering prosthesis may be referred to as a main device and thesecondary or branch prosthesis may be referred to as a secondary orbranch device. In one variation, the tube that is disposed in theprosthesis can be releasably secured to the prosthesis so that it can bewithdrawn after the guide device, which also can facilitate alignment ofthe side opening of the prosthesis with the branch passageway, has beendelivered into the branch passageway. In another variation, theprosthesis can be provided with more than one side opening orfenestration (e.g., the prosthesis can have two side openings orfenestrations) and a tube, which can be releasably secured to theprosthesis, for each opening. In this configuration, each tube has anoutlet positioned in the vicinity of a respective one of the openings sothat a device such as a guidewire can be delivered through eachprosthesis tube lumen and into a branch passageway. In this manner, aguidewire for guiding a catheter through a vessel and then into a branchvessel can be delivered simultaneously with the prosthesis and thendelivered into the branch vessel.

The prosthesis can be in the form of a stent, graft, stent-graft or thelike. Exemplary uses include, but are not limited to, the treatment ofvascular diseases such as aneurysms and stenoses. For example, thetubular prosthesis is especially useful in the endovascular treatment ofabdominal aortic aneurysms where the proximal neck of the aneurysm isdiseased or damaged and attachment of the prosthesis to the artery abovethe renal arteries is desired.

According to another aspect of the invention, a delivery catheter whichaccommodates the prosthesis tube and the guide devices is used to placethese devices at the desired location. In one embodiment where aprosthesis having two side openings is used, the delivery system isconfigured so that the prosthesis tubes generally extend from theprosthesis to the proximal end of the prosthesis delivery catheter orsystem as a one piece construction. Alternatively, the tubes can extendfrom the prosthesis to a member associated with the delivery catheter orsystem. The member would have two lumens formed therein and the lumenswould extend to the proximal region of the delivery catheter or system.

In one example case, a delivery catheter comprises an axial inner andouter member arranged for relative axial movement therebetween. Theouter member or sheath is tubular and the inner member has a pluralityof lumens (e.g., two) formed therein and extending the length thereof.Each prosthesis tube can be coupled to or disposed in a respective innermember lumen. In the latter case, the guide tube can extend the entirelength of the lumen and extend from both ends thereof. When aself-expanding tubular prosthesis is used (e.g., a self-expandingstent-graft), it is radially compressed and loaded in the outer tube orsheath at the distal end thereof and in front of the inner member, whichalso may be referred to as a plunger or pusher rod. Each prosthesisguide tube is placed to extend the length of a respective lumen in theinner member or plunger. Each prosthesis tube also is arranged in theinner member so that it can move or slide relative to the inner memberor plunger to allow movement of the plunger or inner member withouttranslating that motion to the prosthesis. Further, the prosthesis tubescan be constructed of material that allows them to easily collapse andhave a minimal effect on the prosthesis profile so that it can bereadily inserted into the sheath. One suitable material is expanded,porous polytetrafluoroethylene (ePTFE).

In the case where the Xcelerant® Delivery System manufactured byMedtronic. Inc. (Minneapolis, Minn.) is modified to accommodate theprosthesis, prosthesis tubes and guidewires, the lumens can beconfigured to exit from the delivery system near or at its proximal end.

Although various delivery system tube/lumen configurations have beendescribed, it should be understood that the tubes/lumens can beassociated with the delivery system in other manners.

Referring to FIG. 1, a tubular prosthesis or endoluminal device inaccordance with the present invention is shown and generally designatedwith reference numeral 200. Prosthesis or endoluminal device 200comprises a tubular wall 201 having openings or fenestrations 202, whichcan be diametrically opposed as shown in the drawing. Prosthesis 200also has a distal end 204, proximal end 206, distal end opening 208 andproximal end opening 210. Proximal end 206 is the end that is to beoriented towards the oncoming flow of blood. In one example case, thisconfiguration facilitates positioning the proximal end portion 203,which is the end portion above openings or fenestrations 202 (see FIG.2A), above the renal arteries when treating an abdominal aortic aneurysmhaving diseased or damaged proximal neck.

Referring to FIGS. 1, 2A and 2B, prosthesis 200 further includes one ormore guide tubes 212, each forming a lumen that can accommodate a guideelement or device 214 in a manner such that the guide element can bereciprocated therein. That is, the guide element can be slidablyarranged in a respective guide tube. Each guide tube end opening oroutlet is arranged so that guide elements 214 pass through respectiveopenings or fenestrations 202 when the guide elements are advanced fromthe position shown in FIG. 2A to the position shown in FIG. 2B. Allguide tubes described herein can be configured and/or sized anddedicated to guidance and/or delivery of one or more selected devicesincluding, but not limited to guidewires, guide catheters, and/orsteerable guide catheters as described above. In the illustrativeconfiguration, each guide tube is shown disposed inside the prosthesiswith the guide tube outlet arranged below and adjacent to a respectiveside opening or fenestration. The guide tube outlets, however, canoverlap the side openings or fenestrations as shown, for example, inFIGS. 3A-B and 4B-C.

In FIGS. 3A-B, the guide tube outlets are shown overlapping the sideopening fenestration 302. Prosthesis 300 otherwise is the same asprosthesis 200. Accordingly, prosthesis 300 includes corresponding sideopenings or fenestrations 302, distal end 304, proximal end 306, adistal end opening (not shown), proximal end opening 310. Guide tubes314 similarly allow guide elements to slide therethrough and be advancedfrom a retracted state (FIG. 3A) to an extended or deployed state (FIG.3B).

Guide elements 214 and 314 can be wire elements having distal endportions having shape memory set curved or bent configurations as shownin 2B or 3B. The guide elements can be formed, for example, such thatthe distal portions form with the adjacent portion an angle of about 60to 120°. Any suitable shape memory material such as nitinol can be used.Methods for providing nitinol wire with a memory shape are well known inthe art. For example, nitinol wire can be placed in the desired shape(e.g., that shown in FIG. 2B or 3B) and heated for about 5-15 minutes ina hot salt bath or sand having a temperature of about 480-515° C. It canthen be air cooled or placed in an oil bath or water quenched dependingon the desired properties.

Referring to FIG. 4A, a variation of a prosthesis guide tube is shownand designated with reference numeral 414. This guide tube has a curvedend and side opening, which together assist in directing the guideelement out of the prosthesis side opening and into a target branchpassageway. Guide element 414 can be an elastic or superelastic wiresuitable for passing through tortuous passageways that one may encounterin the human vasculature and need not have a memory shape. Guide element414 can be a conventional guidewire. The guide element 414, however, cancomprises shape memory material and have its distal end portion formedwith a preset memory shape configuration such as shown in any of FIG. 4Cor as described above in connection with FIGS. 2B and 3B.

Prosthesis 400 is the same as prosthesis 200 with the exception thatguide tubes 414 have outlets with different configurations as describedabove and they overlap openings or fenestrations 402. Accordingly,prosthesis 400 includes corresponding tubular member 401, side openingsor fenestrations 402, distal end 404, proximal end 406, a distal endopening (not shown), and proximal end opening 410. Guide tubes 414similarly allow guide elements to slide therethrough and be advancedfrom a retracted state (FIG. 4A) to an extended or deployed state (FIG.4B).

Each guide tube described herein can be releasably secured to the innerwall surface of the prosthesis so that the guide tube can be readilyreleased or detached from the guide tube after deployment and the guidetube retracted as will be described in more detail below. The guidetubes can be lightly adhered to the inner wall surface of the prosthesiswith biocompatible adhesive, releasably secured to the prosthesis withsutures such as sutures 216 as shown in FIG. 2A, or releasably securedto the prosthesis with other means. In the case of sutures, the suturesare wrapped around the guide tubes and sewn into the prosthesis tubularwalls with a free end that can be pulled to release the guide tubes fromthe prosthesis. The free end can terminate near the prosthesis and bearranged for manipulation with instruments endoscopically.

Referring to FIG. 5 an exemplary prosthesis delivery system inaccordance with the invention is diagrammatically shown and generallydesignated with reference numeral 700. The illustrative system comprisesprosthesis 200′ and a prosthesis delivery catheter comprising central orinner tube T, inner member (plunger or pusher rod) P and outer member(tubular sheath) 40.

Prosthesis 200′ is the same as prosthesis 200 with the exception thatprosthesis 200′ is shown with a proximal bare spring S secured thereto.Spring S is an annular member comprising a wire having an undulatingconfiguration with a plurality of proximal apices. The spring has aradially outward bias so that when it is released from a radiallycollapsed or restrained state it expands outwardly to secure theproximal portion of the prosthesis to the target passageway wall. Any ofthe prosthesis described herein may include such a spring at either orboth ends thereof depending on the application. It should be understood,however, that other anchoring means can be used instead of one or moreend springs or in combination therewith. Prosthesis 200′ also can bescalloped or provided with a cutout 230 (shown in dashed line) as canany of the prosthesis described herein when suitable for the intendedapplication. For example, when the prosthesis is used to bypass anabdominal aortic aneurysm and its proximal portion placed above therenal arteries, cutout 230 can be provided to allow blood flow to thesuperior mesentery artery.

Tubular sheath 40 surrounds pusher rod P, which has formed therein alongits entire length a center lumen and two diametrically opposed sidelumens. Tubular sheath 40 and pusher rod P are axially movable relativeto each other. Inner tube T, which may be sized to slidably receive aguidewire, is slidably disposed in the central lumen of pusher rod P,and guide tubes 212 are slidably disposed in the diametrically opposedlumens as shown. Pusher rod P and inner tube T are axially movablerelative to another as are pusher rod P and prosthesis or guide tubes212. Each tube 212 has one end portion that is releasably secured to theinner tubular surface of prosthesis tubular wall 201 and another portionthat extends through the length of a respective pusher rod P lumen tothe proximal end of pusher rod P (or the proximal region of the deliverysystem). The proximal end of tube T can be enlarged to form a knob K1 asshown in FIG. 5 to accommodate manipulation of tube T. Similarly, pusherrod P is shown with an enlarged proximal end or knob K2, which also issuitable for hand manipulation. The enlarged end portions or knobs canbe integrally formed with the pusher rod and inner tube or formed asseparate elements and secured or coupled to pusher rod P and inner tubeT. In the illustrative embodiment, guide elements 214 pass throughlumens in the proximal end or knob of pusher rod P and are slidablydisposed therein to facilitate relative axial motion between the innermember (pusher rod) and guide elements and allow movement of the pusherrod without translating that motion to prosthesis 200′.

Prosthesis tubes 212 can be constructed of material so that they easilycollapse and minimally affect the prosthesis profile when the prosthesisis in a collapsed state for introduction into the sheath. Suitablematerials include, but are not limited to Dacron® and expandedpolytetrafluoroethylene (ePTFE).

The distal end of tube T can include a restraint R coupled thereto forreleasably restraining prosthesis spring S in a radially closed state asshown, for example, in FIG. 6A and allowing spring S to expand to anopen state as shown in FIG. 6C.

Referring to FIGS. 6A-C, a method of the invention is set forth merelyas an example. In this example, a method is described in connection withdeploying the proximal end portion of prosthesis 200′ upstream of branchvessels BV that are upstream of an aneurysm A. Further, in thisillustrative example prosthesis 200′ is a self-expanding stent graft.

Prior to introduction of the prosthesis delivery catheter withprosthesis 200′ loaded therein, contrast can be injected into the targetarea to assist in imaging the relative positions of the branch vesselsand the prosthesis as is known in the art. The prosthesis deliverycatheter shown in FIG. 5 and comprising outer tube or sheath 40 andinner tube or pusher rod P can be used to endovascularly deliver theprosthesis to the target site. The catheter can be introduced into thevasculature percutaneously through, for example, one of the femoralarteries and delivered to the target site over a guidewire placed insidetube T.

Once the catheter is positioned for deployment of the prosthesis at thetarget site, pusher rod P is held stationary and the outer tube orsheath 40 withdrawn so that a portion of the prosthesis is graduallyexposed and allowed to expand exposing the side opening or fenestrationas shown in FIG. 6A. Restraint R (pictured in a schematic form,—couldactually include interactive mechanism which move relative to oneanother to at first hold the top of the bare spring S and later bymanipulations known and described in the art releases the spring S asdirected by an operators manipulation of the mechanisms in thecatheter—which are not shown here) restrains spring S to preclude thespring form expanding radially outward so that the stent-graft can bemore easily repositioned if necessary. After prosthesis 200′ has beenexpanded to expose the side opening fenestrations 202 and grosspositioning of the prosthesis has been achieved, a first device 214 suchas a first guidewire is passed through one of the tubes 212 so that theguidewire exits at or is just below a respective side opening orfenestration 214. It is then advanced to pass through fenestration 214.As it is further advanced, conformation of alignment is achieved if thewire can be successfully advanced into the branch vessel (FIG. 6B). Theguidewire can be slightly retracted and the prosthesis repositioned toimprove alignment without the loss of control over the wire. Thisprocedure is repeated for the other branch vessel with the other orsecond guidewire 214. The containment of the first guidewire in thefirst tube minimizes or eliminates the risk of having the firstguidewire inadvertently fall out the branch vessel while manipulatingthe second guidewire.

Having each guidewire contained in a dedicated lumen in the deliverysystem over most of its length, can minimize or eliminate the risk ofentanglement with other devices. With each guide tube positioned in thevicinity of a fenestration, cannulation of the fenestration can besimplified, which can significantly reduce guidewire and cathetermanipulation as compared to conventional approaches. When each guidewireis introduced through the main delivery system, the need for secondaryaccess for either guidewire is eliminated.

The prosthesis guide tubes can be configured and/or sized to accommodateguide catheters, which can be steerable guide catheters. The guidecatheter can assist with navigation of the guidewire between thefenestration and branch vessel. Similar advantages to those describedabove may be achieved.

Referring to FIG. 6C, the delivery system is removed after guidewireaccess has been achieved for all branches and the guidewires left inplace. Prior to or during the withdrawal of the delivery system, tubes212 are detached from the prosthesis. In the case where each tube islightly adhered to the inner wall of the prosthesis, the pusher rod canbe slowly retracted (the prosthesis being fully expanded and secured inplace) as shown in FIG. 6C to remove tubes 212 without displacingstent-graft 200′. Where tubes 212 are attached with a wire or suture,the wire or suture can be manipulated independently to release tubes 212from the prosthesis. The guidewires most likely may need to be pushedforward slightly during removal of the system to prevent retracting theguidewires as well. This type of guidewire manipulation is commonpractice when exchanging devices over guidewires. Balloons can be addedto the guidewires in a manner similar to PercuSurge Guardwire Plus typedevices, e.g., see U.S. Pat. Nos. 6,312,407 and 6,217,567, to anchorthem in position during delivery catheter removal.

FIG. 7 diagrammatically illustrates a bifurcated tubular prosthesis200″, which can be in the form of a stent-graft, positioned to bypassaneurysm A, which in this example is an abdominal aortic aneurysm.Prosthesis 200″ is similar to prosthesis 200′, but comprises tubularwall 201″, which has a bifurcated configuration. In use, openings orfenestrations 202 are aligned with renal arteries RA with theipsilateral leg of the prosthesis extending into one of the iliacarteries. The guidewires then are advanced into the renal arteries,guide tubes 212 detached from the prosthesis and the delivery catheter(including sheath 40, pusher rod P and tube T) and the guide tubeswithdrawn. The contralateral leg of the prosthesis is shown in dashedline and can be delivered endovascularly through the other femoral andiliac artery and coupled to the main body of prosthesis 200″ inaccordance with conventional techniques. The proximal end of prosthesis200″ also can be scalloped or provided with a cutout 230 to allow bloodflow to the superior mesentery artery as described above.

Referring to FIG. 8, another prosthesis in accordance with the inventionis shown and generally designated with reference numeral 500. Prosthesis500 is a stent-graft having a tubular portion 501 comprising anysuitable graft material, annular undulating wire spring elements orstents 518 which structurally support tubular graft 501 and are securedthereto using conventional techniques. Tubular graft portion 501 can bepositioned on the interior and/or exterior of the wire spring elements518. Undulating wire support springs 522 can be provided at both ends oftubular graft 501 to provide radial strength and also can be positionedon the interior and/or exterior thereof. Bare springs 520, which cancorrespond to spring S described above, also have an undulatingconfiguration and have a radially outward biased configuration when afree state (e.g., a released state). In this manner, they serve tosecure the graft against the wall forming a lumen in which theprosthesis is to be placed. Springs 520 can be attached to either orboth ends of tubular graft 501 depending on the desired anchoring at thetarget site. It should be understood, however, that other anchoringmeans can be used in lieu of springs 510 or in combination with eitheror both springs 520. The spring elements or stents, support springs, andbare springs can be of any suitable material as would be apparent to oneof ordinary skill in the art. One suitable material is nitinol. Thegraft material also can be any suitable material such as Dacron® orexpanded polytetrafluoroethylene (ePTFE).

Tubular member 501 includes one or more openings or fenestrations 502,which can be the same as openings or fenestration 202, 302 or 402, and aguide tube 512 associated with each opening or fenestration in the samemanner as described above in connection with guide tubes 212, 312, or412. Radiopaque markers 524 also can be provided to facilitatepositioning openings or fenestrations 502 adjacent to the branch vesselopening(s). Such markers can be secured to the prosthesis with anysuitable methods, i.e., sutures.

Referring to FIG. 9, another prosthesis in accordance with the inventionand generally designated with reference numeral 600 is shown. Prosthesis600 is a bifurcated stent-graft having a modular construction, whichincludes portions 600 a (having and ipsilateral leg portion) and 600 b(the contralateral leg portion) to facilitate delivery and deployment ata bifurcated passageway such as where the aorta branches to the iliacarteries. The contralateral leg portion 600 b can be coupled to mainportion 600 a in situ as is as is known in the art. Stent-graft portion600 a comprises a bifurcated tubular member 601 comprising any suitablegraft material as described above and annular undulating wire springelements or stents 618, which structurally support bifurcated tubulargraft 601 as is conventional in the art. Tubular graft portion 601 canbe positioned on the interior and/or exterior of the wire springelements 618. Undulating wire support spring 622 can be provided at theproximal end of prosthesis 600 and another (not shown) can be providedalong the ipsilateral leg portion of tubular graft 601 to provide radialstrength and also can be positioned on the interior and/or exteriorthereof. Bare spring 620 can be the same as bare spring 520 with thesame radial outward biased configuration. A similar spring can be placedat the distal end of the ipsilateral leg portion of tubular graft 601 incombination with the proximal spring or alone depending on the desiredfixation. It should be understood, however, that other anchoring meanscan be used in lieu of springs 620 or in combination with either or bothsprings 620. The spring elements or stents, support springs, and baresprings can be of any suitable material as would be apparent to one ofordinary skill in the art. One suitable material is nitinol. The graftmaterial also can be any suitable material such as Dacron® or expandedpolytetrafluoroethylene (ePTFE).

Tubular member 601 includes one or more openings or fenestrations 602,which can be the same as openings or fenestration 202, 302, 402, or 502and a guide tube 612 associated with each opening or fenestration in thesame manner as described above in connection with guide tubes 212, 312,412, or 512.

Contralateral leg portion 600 b comprises a tubular graft member andannular wire springs or stents 618, which can be secured to the graftmember in the same manner as springs 618 are coupled to bifurcatedtubular graft member 601. Further, graft material can extend into theapices of the proximal spring 626 of the contralateral leg as shown inFIG. 9. Proximal spring 626 can be biased radially outward to enhancethe connection to the contralateral portion of bifurcated tubular member601 when inserted therein.

Radiopaque markers 624 or 628 also can be provided to facilitatepositioning the stent-graft portions at the desired location.

Restraint R can be in different forms. FIGS. 10A-D show portions of adelivery system 10 in accordance with the invention using a proximalspring restraint described in U.S. Patent Application Publication No.2004/0093063A1, the entire disclosure of said application publicationbeing hereby incorporated by reference herein. The vertical dashed lineprovides a reference line to provide correlation between the figures toa common location related to the position of the end spring of theprosthesis (which in the illustrative embodiment is a stent-graft) aselements of the delivery system are manipulated to first partiallydeploy and then fully deploy the proximal end of the stent-graft, whichmay be any of the stent-grafts described herein.

FIG. 10A illustrates the distal tapered tip portion (which is disclosedU.S. Patent Application Publication No. 2004/0093063A1) of the deliverysystem 10 alone and without a stent-graft, while FIGS. 10B-D show closeup views of the tip portion loaded with a stent-graft constructed inaccordance with the present invention, with progressive figures showingdeployment from within a retractable primary sheath 40.

A configuration of the stent-graft deployment system 10 includes atapered tip 12 that is flexible and able to provide trackability intight and tortuous vessels. The tapered tip 12 can include a lumen 14allowing for passage of a guidewire, for example. Other tip shapes suchas bullet-shaped tips could also be used.

The retractable primary sheath 40 (which can be made of semi-rigidmaterial such as PTFE) in an unretracted position contains thestent-graft in a first constrained diameter configuration as shown inFIG. 10B. An outer tube 18, which can correspond to tube T describedabove, is located within the retractable primary sheath 40 and withinthe stent-graft as shown in FIGS. 10B-D. An inner tube 20 within theouter tube 18 serves as a guidewire lumen. The inner tube 20 and theouter tube 18 can move along the longitudinal axis relative to eachother and can also move along the longitudinal axis relative to theretractable primary sheath. A cap 15 is coupled to a distal area or endportion 11 of the inner tube 20 and is further configured to retain atleast a portion of a proximal end of the stent-graft in a radiallycompressed configuration. Actuating members at the operator's end of thecatheter create a relative force in the axial direction to provide acontrolled relative axial movement between the outer tube 18 and theinner tube 20 to precisely control the release of the proximal end ofthe stent-graft (such as proximal springs) from the cap and from theradially compressed configuration.

Referring to FIG. 10B, the stent-graft is located within the retractableprimary sheath 40 in a pre-deployment unretracted position.

FIG. 10C illustrates system 10 with sheath 40 partially retracted. Theproximal end (tip) of the stent-graft is constrained while a proximalportion of the stent-graft (that is now exposed due to the partialretraction of sheath 40) between the end of the sheath 40 and theconstrained proximal end (tip) is partially deployed, which allowslongitudinal repositioning of the stent-graft before releasing theproximal end (the release of the proximal end of the stent-graftprevents repositioning of the stent-graft in a direction toward theproximal end of the stent-graft, while depending on the degree ofexpansion and contact between the stent-graft and the wall of the vesselin which the stent-graft is being deployed, some pull down (movementtoward the distal end of the stent-graft) of the stent-graft ispossible. Deployment of the stent-graft can be halted and thestent-graft repositioned, rotated or moved in either direction axially.

In FIG. 10D, the proximal end of the stent-graft is shown as having beendeployed by the controlled relative axial movement between the innertube 20 and the outer tube 18. In particular, as shown in FIGS. 10B-D,an end cap 15 containing the proximal apices of the end spring to thestent-graft can be formed from a shroud portion of the tapered tip 12,which is coupled to the distal end of the outer tube 18. Within theshroud portion (formed by tubular body portion 16 of the tapered tip 12)can reside a back plate 17 coupled to a distal portion or end of outertube 18 that serves as a proximal stop for the stent-graft. The tubularbody portion 16 of the shroud portion may also include a support(reinforcing) ring 13 near the proximal end of the tapered tip 12 toprovide additional rigidity to the cap and minimize or eliminate therisk of the cap shroud portion 16, which can be made of plasticmaterial, from stretching (or distorting) in diameter. Thisconfiguration can thereby prevent premature release of the proximal endof the stent-graft constrained by the cap (premature stretching couldcreate a gap large enough for the restrained members of the stent-graftto spring loose. Additionally, a proximal lock (retainer 22 is alsocoupled to a distal portion of the outer tube 18. The proximal lock 22can include at least one or a plurality of ribs (or splines) 23 that cantogether with the shroud portion 16 serve as an axial constraint for theend of the stent-graft. The proximal end (or the proximal spring) of thestent-graft cannot deploy until the proximal end of the ribs of theproximal lock clear the end of the shroud portion 16 of the tip.

As shown, the gap 19 between the backplate 17 and the proximal lock 22,can be designed to hold the protruding apices of the proximal spring.The apices straddle the ribs 23 of the proximal lock 22 and remaintrapped between the back plate and the proximal lock until relativemovement between the outer tube 18 and the inner tube 20 exposes the gap19 and releases the apices of the proximal spring as shown in FIG. 10D.In other words, the apices cannot release from the ribs 23 on theproximal lock 22 while the apices remain within the shroud portion 15.When the inner tube 20 and tapered tip 12 assembly are advanced forwardexposing the proximal lock 22, the apices of the proximal spring releasefrom the respective ribs 23 of the proximal lock 22. The release resultsin the deployment of the proximal end of the stent-graft as shown inFIG. 10D. Note that while the apices of the proximal spring remain ingap 19 and within the cap or shroud portion of the tapered tip 12, thewhole of the proximal spring remains axially (longitudinally)constrained as well as radially constrained. The support ring 12,usually made of metal, helps prevent the radial force of the proximalsprings from distorting the shape of the tapered tip and particularlythe shroud portion of the tapered tip.

Although one particular restraint R has been shown, it should beunderstood that other configurations can be used. For example, otherproximal tip deployment systems also described in U.S. PatentApplication Publication No. 2004/0093063A1 can be used as well. Thedisclosure of U.S. Patent Application Publication No. 2004/0093063A1 isincorporated herein in its entirety.

Any feature described in any one embodiment described herein can becombined with any other feature of any of the other embodiments.

Variations and modifications of the devices and methods disclosed hereinwill be readily apparent to persons skilled in the art.

1-11. (canceled) 12: A tubular prosthesis delivery system comprising adelivery catheter having a proximal end portion and a distal endportion, a tubular prosthesis comprising a tubular wall, first andsecond end openings, and a side opening formed in said tubular wallbetween said first and second end openings, said prosthesis beingpositioned in said distal end portion of said delivery catheter, and atube having a first end portion and a second end portion, said tubefirst end portion being disposed in said tubular prosthesis and havingan end opening in the vicinity of said side opening and said tube secondend portion extending to said proximal end portion of said deliverycatheter. 13: The delivery system of claim 12, including a pusher rodslidably disposed in said catheter and having an end portion facing saidtubular prosthesis. 14: The delivery system of claim 13, wherein saidtube is releasably secured to said tubular prosthesis. 15: The deliverysystem of claim 12, wherein said tube is releasably secured to saidtubular prosthesis. 16: The delivery system of claim 12, wherein saiddelivery catheter comprises a sheath and a pusher rod slidably disposedtherein, said pusher rod having a lumen formed therein and extending inan axial direction thereof, and said prosthesis tube extending throughsaid pusher rod lumen. 17: The delivery system of claim 16, wherein aguidewire extends through at least a portion of said lumen and saidprosthesis tube. 18: The delivery system of claim 12, wherein saidprosthesis has a radially collapsed state and a radially expanded state,said tubular prosthesis being in said collapsed state. 19-35. (canceled)